Four years ago, Robert Gillespie was co-head of global investment banking at UBS with a staff of several thousand working for him and responsibility for the fifth-largest capital markets business in the world.

After a short-lived retirement, Gillespie emerged last week as the latest senior banker to make the switch from beleaguered bulge-bracket to independent boutique, joining Evercore’s European business as a senior managing director.

Unable to offer debt financing as a quid pro quo for advisory mandates and struggling with endemic structural problems, full-service banks are finding their dominance challenged by boutiques.

Last week, Evercore picked up the sole mandate to advise Swiss Re on its £1.8bn (€2bn) capital injection by Warren Buffett. Last month it was named alongside Morgan Stanley as adviser to US pharma company Wyeth on its $70bn (€55bn) acquisition by rival Pfizer.

Francois Maisonrouge, a healthcare banker at Credit Suisse who joined Evercore in 2007, said: “With the economics of financing so much more favourable than those of giving advice, large banks moved from deal making to deal processing. Clients are now realising that big banks have demands that aren’t completely aligned with their own interests.”

The cull in investment banking has left talented bankers seeking a home and boutiques, free from the balance sheet constraints facing their competitors, are well-placed to capitalise.

Malik Karim, founder and managing director of Fenchurch, said: “Two years ago, it was a challenge to attract good people. Now we have five world-class people for every slot at every level of the business. People are attracted by the boutique model and are realistic about pay and compensation.”

The financial pull that big banks once exerted has been undermined by the curb on compensation, and many bankers are disillusioned after years of being paid a large proportion of their bonuses in stock.

The opportunity to work on deals away from the strictures of working for a large bank is also a big driver. Gillespie said: “It is not necessarily an issue of compensation. A lot of bankers have been ground down by not being able to do their job and look after clients.”